Checking mechanism



T. DE W. HUBBELL CHECKING MECHANISM June 1 1926. 1,586,901

Filed Oct. 8. l923 FWZ F195 v INVENTOR. Teoaore Hqd/ v BY www;

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'LITHEODORIE` DE lll/ITT HUBBELL, OE LOSVANGELES, CALIFORNIA.

CHECKING MECHANSM.

Application filed October 8, 1923. SeralNo. 667,400.

My invention relates generally to checking mechanisms adapted for association with anelement which is forciblymoved in one direction from a-position to which it is normally urged, to retard or check the movement of the element to its urged position.

Specifically, my. inventionY relates to a checking mechanism, which is particularly adapted, although not necessarily, for checking themovement of'a doorto closed position in orderv to prevent slamming of the door.

It4 is a purposeof my invention to provide a door checking mechanisinwhich operates to check or retardthe closing movement of a door, not gradually as in similar mechanisms heretofore proposed, but only when the door reaches a position adjacent its closed position, so that the period which the door remains in open position is greatly reduced; v

vlt is also a purpose of my invention to provide a checking mechanism of eXtremely simple, inexpensive and durable construction and one which includes a piston and cylinder, the latter containing a checking fluid and positioned vertically to eliminate the necessity of providing a stuffing boX around the piston rod as is necessary in other checking mechanisms to prevent the escape ofthe checking;` fluid.

A further purpose of my invention is provision of a checking mechanism,including4 valve controlled ports in the piston with one of the valves adjustable toA vary the checking action of the mechanism as desired.

I will describe onlyv one form of checking mechanism embodying` my invention and will then point out the novel features thereof in claims.

In the accompanying drawings z Figure 1 is a view showing a screen door 'having applied thereto one form of checking mechanism embodying my invention;

Figure 2 is an enlarged vertical sectional view of the checking device comprised in the mechanism shown in Figure 1;

Figure .is a fragmentary sectionalview ofthe device shown in Figure 2, but in another position;

Figure 4- is a fragmentary detail view of the connection between the piston and pis ton rod offthe device shown ini Fi. ure 2;

..,., A J l iwi-ft Figures t and 6 are sectional viens teken on the lines 5 5v and 6 6, respectively, of Figure 3.

Similar reference characters referto similar part-s in each of the'severalfviews.

Referring speciticially to the drawings and particularly to Figure 1, my invention in vits present embodiment is shown as applied to a screen door 15, which is hinged as indicated at 16 to swing to open or closed' position in the usual manner. Thechecking mechanism includes a bracket 17 secured to the wall ofthe opening which the door controls, and another bracket 18 secured to the frame of the door 15. A link 19 is pivoted at its upper end to thebracket 17, and at its lower end to the horizontalportion Qt) ofI an Lshaped lever 21, the latter in turn being pivoted at its upper end to the bracket 18,

A coil spring 22 is associated with the door 15, so as to normally urge the door to closed position, and a checking device is associated with the link 191and the lever 21 to retard the-movement of the door to closed position under the Iaction of the spring 9.2. This checking device is shown inFigures 2 andB," as comprising a cylinder 23 closedv at its lower end and' provided with an extension 24' through which a piny 25 (Figure 1') extends for the purpose of pivotally connecting the lower-endet' the cylinder to the horizontal portion 2O of the lever 21. lnorder that this connection may be rendered adjustable for a purposewhich will behereinafter described, the horizontal portion 2O is formedwith a series of openings 26 through any one 1of'which-the lpin 25 may extend for pivotally connecting the le'- ver and cylinder.

The upper end oflthecylinderfis normally open but is adapted to be closed by a screw disc -27, and the latter is 'formedi with an openingclosed by plug 28A and through which a checking fluidy such as oil or the like may beintroduced intoy the. cylinder. TheA disc 27 is also formed with an axial opening through which a piston rod 29 slides, the lower end of` the piston being operatively connected-to apiston 3D, which is slidably fittedwithinthecylinder 23. The piston '30 is provided with an axially'disposed duct 31,and .extending-intocthis'duct isl a reduced 'extension 320i:a "thelowerfiid of the-rod 29.' The; extension 32 provided "svitl' an which extends a connecting pin 34, the latter also extending through a suitable transverse opening in the piston 30 whereby they rod 1s operatively connected to the piston. It will i tflt'tt e' 'W' 'flbl ce no eu na .ne opening of) is considera y larger thanthe diameter of the pin 311-, so

Vv"that a limite-il vertical*movement of the rod -checking fluid therethrough.

The piston 30 is also formed with a second duct 3G, through which the checking fluid is adapted to circulate in controlling relative movement of the piston and cylinder. 1 A valve designated generally at 3T, is adapted to contr l the passage of the checking fluid through the duct This valve,

in the present instance, comprises an elongated Vbody or shank having a threaded portion 37a extending through the disc 27 and formed at its upper end with a knurled head 37". Below lthe threaded portion 37a Ythe body is formed with a flat face 37C,

and at the lower end of this flattened portion vthe body is provided with a valve head 37d, which as clearly shown in Figure b, is of circular form in contradistinction to the flat-portion 37C which as shown in Figure 5 is of semi-circular form in cross section. By virtue of the threaded connection between` the disc 27 and the valve 87, the latter is capable of vertical adjustment within a cylinder 23, to vary the normal position ofthe head 37d with respect to the piston 30.V

As shown in Figure 1, the upper end of the piston rod 29, is pivotally Connected to the link 19, but by reason of the mounting of the cylinder 23, and the movement of tue linkj19, and lever`21, during vmovement ofthe door, the rod vis secured against longitudinal movement while the cylinder 23 moves longitudinally with respect to the rod.

Yln operation, the door 15 when moved to Y open vposition. against the action of the spring causes the lever 21 to swing in Va direction away from the link 19, thereby dr.wing the cylinder 23 downwardly while Vthe piston remains stationary. Initial downward niioveinent ofthe cylinder 23 effects a slight dow ward movement of the piston 30, so that the latter moves from the position shown in Figure 3, to that shown in Figure 2. In Vthis position of the piston which is defined by the connecting pin Sli, the valve 35 is unseated with respect to .the` upper end of the duct .31, so that the rchecking fluid above theplston is free tothe latter to the former, a valve portion pass to a point below the piston during the downw.-,.rd move ient of the cylinder. It will thus be seen that as the downward movement of the cylinder is unrestricted the opening movement of the door is likewise unrestricted.

lVhen the door is released, the spring operates to move the door to closed position. However, the door is restricted during a` major portion of this movement because ofthe flattened portion 3T of the valve 37. It will be understood that during the closing movement of the door, the cylinder Y 2S is moved upwardly, thereby causing the valve 35 to seat and close the upper end of duct 31, to prevent upward passage of theV fiuid through the duct. l'clowever, the fluid is free to pass through the duct 36, because of the flattened portion 37C, and until the cylinder occupies such a. position that the head 37d is disposed with'- in the duct 3G, as shown in Figure 53. ln this position of the head 37d, the duct is substantially closed thus restricting the npward passage of the fluid through the duct and thereby perceptibly checking or retarding the movement of the cylinder and with it the closing movement of the door. From this operation itwill be ma iifest that the door in its closing movement is unchecked until the door is adjacent closed position thereby reducing the time that .the door actually occupies open position. This is of great advantage in screen doors as will be obvious.

By reason of the adjustability of the valve 87, the instant at which the checking mechanism functions to actually checkthe closing movement of the door can be varied as desired, because by vertically adjusting the valve the position of the head 87d with respect to the piston 30, is likewise varied. The'adjustable connection between the cylinder 23 and the lever 21 provides further means for adjust-ing the checking action of the mechanism. n Y

Although I have herein shown and described only one form of checking mechanism embodying my invention, it is to be understood that various changes and modifications may be made herein without departing from the spirit of the invention and the spirit and scope of the appended claims.

lilhat l claim is 1. A Checking mechanism comprising a cylinder adapted to be pivotally arranged on a swinging support, a piston rod extending into the cylinder adapted to be connected to another swinging support, a piston head operating in the cylinder to function against a body of liquid contained therein and provided with an axially disposed duct, means to permit slight relative movements of the rod and the piston Vhead and for mounting Leseeol formed ou the rod beyond one face of the head and adapted to respectively seat against and unseat from said tace ot' the head on actuations oi the cylinder and said rod, the head having a second duct extending theretlnough in parallelism with the lirst said duct, and an elongated body adjustable longitudinally of the cylinder from a point Without same and through said second named duct and provided with portions respectively coacting with the Walls ot the said second named duct to control 'movements of fluid under relatively different conditions through said second duct in time 'ith relative movements of the cylinder and said head and in time with movements oiE the valve portion of the rod With respect to the said oneI tace ot the head.

2. A door check embodying a fluid containing cylinder havino a piston head, a rod movable through one end of the cylinder and connected for sliding movement with the head and provided with a valve portion adapted to coact with one tace of the head on relative movement ot the piston and said cylinder, the head having' a duct receiving a portion ot the rod and the said duct being ot greater diameter' than the rod and of less diameter than the aforesaid valve portion,-

the said head having a second duct, and an elongated body adJustable longitudinally of the cylinder and coacting With said second duct for determining' the passage of fluid therethrough from one side of the head to the otherside thereof in time with movements. ot' the head and said cylinder.

3. A door check embodying a fluid containing cylinder having a piston head, a rod movable through one end ot the cylinder and connected ior sliding movement With theV head and provided with a valve portion adapted to coact with one tace of the head on relative movement ot the piston and said cylinder, the head having a duct receiving portion oic the rod and the said duct being of greater diameter than the rod and of less diameter than the aforesaid valve portion, the said head having a second duct, and an elongated body adjustable longitudinally of the cylinder and coa-cting ivith said second duct 'for determining the passage of fluid therethrough from one side of the head to the other side thereof in time with movements of the head and said cylinder, the reduced portion oi the rod having an opening therein and a pin passing through the opening and through the head for attaching the head to said reduced portion and for perinitting the aforesaid relative movements of 'the head and said rod.

THEODORE DE WlTT HUBBELL. 

